The reason why Google got so involved in security over the last decade is Operation Aurora. Nearly ten years ago, Google got hit by one of the most startling cyberattacks on an American company, as the Chinese military managed to penetrate Google. This was a massive wake-up call for Google, resulting in the hiring of cyberexperts from the NSA and Silicon Valley to ensure this would never happen again:
Google poached cyberexperts from the National Security Agency and Silicon Valley. It built a threat analysis group on a par with those at the top intelligence agencies and designed a new security infrastructure. It also created a new team, called Google Project Zero, to hunt for critical security flaws in technology outside Google.More details at NY Times.
“When the Chinese attacked in 2010, that was an entire wake-up call for us; our entire attitude changed,” said Eric Schmidt, a member of Alphabet’s board of directors who was chief executive of Google at the time of incident, in an interview.